[zero] add chunk_managerV2 for all-gather chunk (#1441)

Author: 1SAA

colossalai/gemini/update/__init__.py

@@ -1,2 +1,3 @@
 from .chunkv2 import ChunkV2
+from .chunk_mgrv2 import ChunkManagerV2
 from .search_utils import clasify_params, search_chunk_configuration

colossalai/gemini/update/chunk_mgrv2.py

@@ -0,0 +1,221 @@
+import torch
+from typing import Optional, Dict, Deque, Set, List, Tuple, Iterable
+from collections import deque
+
+from colossalai.utils import get_current_device
+from colossalai.tensor import ColoTensor
+from colossalai.gemini.chunk import ChunkFullError, TensorState
+from colossalai.gemini.update import ChunkV2 as Chunk
+
+
+class ChunkManagerV2:
+    """
+    A manager class to manipulate the tensors in chunks.
+
+    Args:
+        chunk_configuration (Dict[int, Dict]): the configuration dictionary of this chunk manager.
+        init_device (torch.device): optional, the device on which the chunk is initialized. The default is None.
+        pin_memory (bool): if ture, all chunks have a piece of pinned memory in CPU.
+    """
+
+    def __init__(self, chunk_configuration: Dict[int, Dict],
+                 init_device: Optional[torch.device] = None,
+                 pin_memory: bool = False) -> None:
+
+        self.device = init_device or get_current_device()
+        self.size_config: Dict[int, int] = dict()
+        self.kwargs_config = chunk_configuration
+        for k, v in self.kwargs_config.items():
+            self.size_config[k] = v.pop('chunk_size')
+            v['init_device'] = self.device
+            v['pin_memory'] = pin_memory
+
+        self.chunk_groups: Dict[str, Deque] = dict()
+        self.tensor_chunk_map: Dict[torch.Tensor, Chunk] = dict()
+        self.accessed_chunks: Set[Chunk] = set()
+        self.lazy_release_tensors: List[torch.Tensor] = list()
+        self.total_mem: Dict[str, int] = {'cpu': 0, 'cuda': 0}
+
+    def append_tensor(self, tensor: ColoTensor, group_type: str, config_key: int) -> None:
+        """Append a tensor to a chunk.
+        """
+        assert tensor not in self.tensor_chunk_map
+        assert isinstance(tensor, ColoTensor), "Please feed ColoTensor to this ChunkManager"
+        assert config_key in self.size_config
+
+        chunk_size = self.size_config[config_key]
+        chunk_kwargs = self.kwargs_config[config_key]
+        group_name = "{}_{}".format(group_type, config_key)
+        chunk_group = self.__get_chunk_group(group_name)
+
+        try:
+            # append the tensor to the last chunk
+            chunk_group[-1].append_tensor(tensor)
+        except (IndexError, ChunkFullError):
+            # the except statement will be triggered when there is no chunk or
+            # the last chunk in the chunk group is full
+            # this will create a new chunk and allocate this chunk to its corresponding process
+            if chunk_group:
+                # the chunk group is not empty
+                # close the last chunk
+                self.__close_one_chunk(chunk_group[-1])
+
+            if tensor.numel() > chunk_size:
+                chunk_size = tensor.numel()
+            chunk = Chunk(
+                chunk_size=chunk_size,
+                process_group=tensor.process_group,
+                dtype=tensor.dtype,
+                **chunk_kwargs
+            )
+
+            chunk_group.append(chunk)
+            chunk.append_tensor(tensor)
+            self.__add_memory_usage(chunk.memory_usage)
+
+        self.tensor_chunk_map[tensor] = chunk_group[-1]
+
+    def close_all_groups(self):
+        """Close all the chunks of all groups.
+        """
+        for group_name in self.chunk_groups:
+            self.__close_one_chunk(self.chunk_groups[group_name][-1])
+
+    def access_chunk(self, chunk: Chunk) -> None:
+        """Make the chunk can be used for calculation.
+        """
+        if chunk in self.accessed_chunks:
+            return
+        self.__sub_memroy_usage(chunk.memory_usage)
+        chunk.access_chunk()
+        self.__add_memory_usage(chunk.memory_usage)
+        self.accessed_chunks.add(chunk)
+
+    def release_chunk(self, chunk: Chunk) -> None:
+        """Scatter the chunk in CUDA.
+        """
+        if chunk not in self.accessed_chunks:
+            return
+        if chunk.can_release:
+            self.__sub_memroy_usage(chunk.memory_usage)
+            chunk.release_chunk()
+            self.__add_memory_usage(chunk.memory_usage)
+            self.accessed_chunks.remove(chunk)
+
+    def move_chunk(self, chunk: Chunk, device: torch.device) -> None:
+        """Move the shard of the chunk to the target device.
+        """
+        if not chunk.can_move or chunk.device_type == device.type:
+            return
+        self.__sub_memroy_usage(chunk.memory_usage)
+        chunk.shard_move(device)
+        self.__add_memory_usage(chunk.memory_usage)
+
+    def trans_tensor_state(self, tensor: torch.Tensor, state: TensorState) -> None:
+        """Transit tensor state according to pre-defined state machine.
+        """
+        chunk = self.tensor_chunk_map[tensor]
+        chunk.tensor_trans_state(tensor, state)
+
+    def reduce_chunk(self, chunk: Chunk) -> bool:
+        """Reduce or all reduce the chunk.
+        """
+        if not chunk.can_reduce:
+            return False
+        self.__sub_memroy_usage(chunk.memory_usage)
+        chunk.release_chunk()
+        self.__add_memory_usage(chunk.memory_usage)
+        return True
+
+    def copy_tensor_to_chunk_slice(self, tensor: torch.Tensor, data: torch.Tensor) -> None:
+        """
+        Copy data to the chunk.
+
+        Args:
+            tensor (torch.Tensor): the tensor used to retrive meta information
+            data (torch.Tensor): the tensor to be copied to the chunk
+        """
+        chunk = self.tensor_chunk_map[tensor]
+        chunk.copy_tensor_to_chunk_slice(tensor, data)
+
+    def get_chunk(self, tensor: torch.Tensor) -> Chunk:
+        """
+        Return the chunk owning the tensor.
+
+        Args:
+            tensor (torch.Tensor): a torch tensor object
+        """
+        return self.tensor_chunk_map[tensor]
+
+    def add_lazy_release_tensors(self, tensors: List[torch.Tensor]) -> None:
+        """
+        Add tensors to the buffer for lazy release.
+
+        Args:
+            tensors (List[torch.Tensor]): the tensors to be released lazily
+        """
+        self.lazy_release_tensors.extend(tensors)
+
+    def exec_lazy_release(self) -> None:
+        """
+        Execute release for tensors added to the lazy release buffer.
+        """
+
+        for chunk in self.get_chunks(self.lazy_release_tensors):
+            self.release_chunk(chunk)
+        self.lazy_release_tensors.clear()
+
+    def __repr__(self) -> str:
+        msg = ['Chunk Manager Information:\n',
+               'Total memory: ' + ', '.join([f'{k}={v}B' for k, v in self.total_mem.items()]) + '\n']
+        for group_name, group in self.chunk_groups.items():
+            msg.append(f'Group {group_name}:\n')
+            for i, chunk in enumerate(group):
+                msg.append(f'[{i}] {chunk}\n')
+        return ''.join(msg)
+
+    def get_chunks(self, tensors: Iterable[torch.Tensor]) -> Tuple[Chunk, ...]:
+        """
+        Get all chunks owning the input tensors.
+
+        Args:
+            tensors (Iterable[torch.Tensor]): the tensors used to look for chunks
+        """
+        chunks = []
+        for tensor in tensors:
+            chunk = self.get_chunk(tensor)
+            if chunk not in chunks:
+                chunks.append(chunk)
+        return tuple(chunks)
+
+    def add_extern_static_tensor(self, tensor: torch.Tensor) -> None:
+        """Add extern static tensor to chunk manager.
+        Those tensors won't be managed by chunk manager, but we want to monitor memory usage of them.
+        They are "static", which means their shape, dtype, device never change.
+        Thus, their memory usage never changes.
+
+        Args:
+            tensor (torch.Tensor): An extern static tensor. E.g. optimizer state.
+        """
+        assert tensor not in self.tensor_chunk_map
+        self.total_mem[tensor.device.type] += tensor.numel() * tensor.element_size()
+
+    def __get_chunk_group(self, group_name: str) -> Deque:
+        """Register a chunk group.
+        """
+        if group_name not in self.chunk_groups:
+            self.chunk_groups[group_name] = deque()
+        return self.chunk_groups[group_name]
+
+    def __close_one_chunk(self, chunk: Chunk):
+        self.__sub_memroy_usage(chunk.memory_usage)
+        chunk.close_chunk(self.device)
+        self.__add_memory_usage(chunk.memory_usage)
+
+    def __sub_memroy_usage(self, usage: Dict[str, int]):
+        for k, v in usage.items():
+            self.total_mem[k] -= v
+
+    def __add_memory_usage(self, usage: Dict[str, int]):
+        for k, v in usage.items():
+            self.total_mem[k] += v

tests/test_gemini/update/test_chunk_mgrv2.py

@@ -0,0 +1,76 @@
+import torch
+import colossalai
+import pytest
+import torch.multiprocessing as mp
+from functools import partial
+from colossalai.gemini.update import ChunkManagerV2
+from colossalai.testing import rerun_if_address_is_in_use, parameterize
+from colossalai.utils import free_port
+from colossalai.tensor import ProcessGroup, ColoTensor, ColoTensorSpec
+from tests.test_tensor.common_utils import debug_print
+
+CUDA_MEM_0 = {False: 512, True: 1024}
+CUDA_MEM_1 = {False: 0, True: 1024}
+CPU_MEM = {True: {True: 0, False: 0}, False: {True: 512, False: 0}}
+
+
+@parameterize('keep_gathered', [True, False])
+@parameterize('pin_memory', [True, False])
+def exam_chunk_memory(keep_gathered, pin_memory):
+    pg = ProcessGroup()
+
+    debug_print([0], "keep_gathered: {}, pin_memory: {}".format(
+        keep_gathered, pin_memory))
+
+    params = [ColoTensor(torch.rand(8, 8), spec=ColoTensorSpec(pg)) for _ in range(3)]
+    config = {
+        2: dict(
+            chunk_size=128,
+            keep_gathered=keep_gathered
+        )
+    }
+
+    chunk_manager = ChunkManagerV2(config, pin_memory=pin_memory)
+    assert chunk_manager.total_mem['cpu'] == 0
+    assert chunk_manager.total_mem['cuda'] == 0
+
+    for p in params:
+        chunk_manager.append_tensor(p, 'param', 2)
+    chunk_manager.close_all_groups()
+    assert chunk_manager.total_mem['cpu'] == CPU_MEM[keep_gathered][pin_memory]
+    assert chunk_manager.total_mem['cuda'] == CUDA_MEM_0[keep_gathered]
+
+    chunks = chunk_manager.get_chunks(params)
+
+    for chunk in chunks:
+        chunk_manager.access_chunk(chunk)
+    assert chunk_manager.total_mem['cpu'] == CPU_MEM[keep_gathered][pin_memory]
+    assert chunk_manager.total_mem['cuda'] == CUDA_MEM_0[True]
+
+    for chunk in chunks:
+        chunk_manager.release_chunk(chunk)
+
+    assert chunk_manager.total_mem['cpu'] == CPU_MEM[keep_gathered][pin_memory]
+    assert chunk_manager.total_mem['cuda'] == CUDA_MEM_0[keep_gathered]
+
+    for chunk in chunks:
+        chunk_manager.move_chunk(chunk, torch.device('cpu'))
+    assert chunk_manager.total_mem['cpu'] == CPU_MEM[keep_gathered][True]
+    assert chunk_manager.total_mem['cuda'] == CUDA_MEM_1[keep_gathered]
+
+
+def run_dist(rank, world_size, port):
+    colossalai.launch(config={}, rank=rank, world_size=world_size, host='localhost', port=port, backend='nccl')
+    exam_chunk_memory()
+
+
+@pytest.mark.dist
+@pytest.mark.parametrize('world_size', [2])
+@rerun_if_address_is_in_use()
+def test_chunk_manager(world_size):
+    run_func = partial(run_dist, world_size=world_size, port=free_port())
+    mp.spawn(run_func, nprocs=world_size)
+
+
+if __name__ == '__main__':
+    test_chunk_manager(2)